US expands probe into Ford engine failures to include two motors and nearly 709,000 vehicles

U.S. auto safety investigators have expanded a probe into Ford Motor Co. engine failures to include nearly 709,000 vehicles. The National Highway Traffic Safety Administration also said in documents posted Monday on its website that it upgraded the investigation to an engineering analysis, a step closer to a recall. The investigation now covers Ford's F-150 pickup truck, as well as Explorer, Bronco and Edge SUVs and Lincoln Nautilus and Aviator SUVs.